WOW What a Week!
It was a really exciting week for eagles! Not only did we learn of Pete
and Kathy’s successful trapping of a beautiful female Bald eagle (V98),
but also, the migration is on. One of the eagles has high-tailed it out
of NY and is now soaring the Canadian skies. Don’t look yet - can
you guess which one?

Hello again
Students/Eagle Lovers!
We have some good news to start off this week. Not only are some of our
eagles on the move now, but we have a new one to follow.

First, the
story of our new eagle, V98.
Usually, March is not a particularly good time for our migratory eagle
trapping efforts; many of the wintering birds have already begun to move
around, and water is opening up making it more difficult to attract eagles
to our bait, since they have more and more of their preferred habitat
available. Nevertheless, last Tuesday, March 9th, Kathy Michell and I
decided to try again, along the Delaware River in southeastern NY (our
border with Pennsylvania). As usual, I left home at 2:30 am, drove for
3 hrs, met Kathy at our trap-site and got the bait and net all set up
before dawn, which at this time of year is coming before 6 am!

…Then,
a little after eight-o'clock, I spotted a large adult gliding toward our
trap site from up-river, on a direct line toward the carcass. This bird
came out of no where, and perched in a tree right about the carcass for
about 5 minutes, watching the squabbling immatures on the carcass, until
it finally decided it wanted in on the action…

In other
news, as you will also see from the latest data, our golden eagle A00
has begun his northward move, about a week earlier than last year. He
is already well into Canada. Unfortunately, Scott and Kathy were not successful
in capturing A00's mate, but as Scott says, there is always next year!

Being at the
right place at the right time certainly describes the capture of V98. This
hungry Bald Eagle, lured to a fresh carcass and caught in the early dawn
light was probably on migration route when she was trapped along the Delaware
River on March 9. Pete writes, “I was wondering whether we caught
a resident breeder or a migrant. It didn't take long to find out.”
Her fueling stop was brief, and because of the transmitter she now carries
we know she is now somewhere in the Adirondack Mountains.

How far did she fly? She was released March 9th at 10:15
Eastern Standard Time (EST), and her most recent signal was recorded March
12th at 17:33 EST. Can you calculate how many hours and minutes these
readings are apart? During this time she traveled 192 miles (309 kilometers).

Challenge
Question #13:
“V98 traveled 192 miles (309 km) between March 9 and March 12.
Calculate her flight speed during this time.” (You may round the
time to make this easier to calculate.)

But don't get too comfortable! Let's step back for a minute. Think about
the information the satellite sends us every two days, and the assumptions
we might be making when we interpret the data.

Try
This!
Close your eyes. Imagine being in your classroom, day and night, with
your eyes closed. Every 2 days, you blink your eyes open for a few seconds.
You ONLY have that time to see what is happening. The rest of the time,
you see nothing but darkness. As a class, consider the conclusions you
might draw, based on your limited observations.

Think about
that image when you interpret satellite data. The satellite only sends
a snapshot representing a moment in time. Consider what might be happening
when we're not looking!

Challenge
Question #14:
"How might an eagle's behavior be different than our migration
map shows? That is, what might an eagle be doing during the time the
satellite is NOT sending us data? Give an example."

Local time
is meaningless to a satellite. Remember, the satellite is zooming around
the earth every 101 minutes, so local times on Earth are a blur.
In Challenge Question #13 we gave you the data recorded in local time (EST).
However, the satellite data time is given to scientists according to Greenwich
Mean Time (GMT). GMT is an international time-keeping standard. It is based
on the local time in Greenwich, England. Greenwich Mean Time is also called
Universal Time (UT).

Read on for a description of GMT and challenge yourself
to learn more about our use of world clocks.

Locate
Greenwich, England. How many time zones away from Greenwich, England
are you?

Eagle
data is given in GMT. What time is it GMT when it is 10:15 EST?

What
time is it GTM when it is 17:33 EST?

Nesting in MA
Nesting under a live camera in MA, the eagle capturing the attention of
thousands of viewers has laid her 2nd egg! Earlier this month the eagle
was caught on camera sitting in her nest for every picture. We asked our
expert, Pete Nye if she could be sitting on eggs already. His reply, “Absolutely!
Many of our birds are down on eggs already. Realize, they sit on them for
over a month, then young are in the nest for 3 more months....it’s
a long nesting season!”

Female
on nest at 10:40, steps off at 10:45 AM to reveal 2 eggs! Toughing
it out at 14:35 the same day.
Credit Eagles
Online

Looking at
these pictures, what can you say about eagle nesting behavior?

Winter
Dining: Discussing Challenge Question #11
An eagle eats 5-10% of its body weight each day. Male bald eagles weigh
8-9 lbs., and females weigh 10-14 lbs. Challenge Question #11 asked,
“How many pounds of food does an eagle need to consume each day? If
you needed the same percentage of food daily, how many pounds would you
need?”
Tom, Heather, Matt, Kristina and Caitlin – all 7th graders from Iselin
Middle School showed us their work to solve the question:

A male
bald eagle weighs about 8.5lbs.

Male
bald eagle: weighs 8.5lbs. = 0.425lbs. at 5%
0.85 lbs. at 10%

Female
bald eagle: weighs 12lbs. = 0.6lbs. at 5%
1.2lbs. at 10%

A male
member of our group weighs 135lbs. To find the equivalent amount of
food he eats to that of an eagle we set up a proportion:
5% = 0.425/8.5 X x/135 = 6.75lbs of food
10% = 0.85/8.5 X x/135 = 13.5lbs of food

5th Graders
in Park Rapids, MN and Ferrisburgh, VT weighing in at 70 and 90 lbs (and
consuming 10% of their bodyweight) would need to eat 7 and 9 lbs of food
each day. Now that’s a lot of “quarter-pounders!”

Adaptations: The Tail - Discussion of CQ #12
“In what ways does the eagle’s tail help sustain their fishing
and scavenging lifestyle?”

Jonathan has done his research! He wrote to us,

“The
tail - is very important for flight and maneuvering. While the bald
eagle is soaring or gliding in flight, the tail feathers are spread,
in order to attain the largest surface area and increase the effect
of thermals and updrafts. The tail also helps to brake the eagle when
landing and assists in stabilization during a controlled dive or swoop
toward prey. The strength of the feathers and the follicles holding
the feathers is quite impressive, while watching the tail move back
and forth and up and down during maneuvers.”

Other great
adaptations included balance while flying, an aid for slowing down when
landing and a signal to others that when the tail is white that the bird
is mature.

Bald
Eagle Adaptations: The Body

This spring
we're looking closely at eagles, from head to toe. Each week, we'll pose
a Challenge Question related to the next week's featured adaptation. Remember:
There's always a WHY behind WHAT you see. So whenever you see an unusual
behavior or body part, ask yourself WHY...

Are
you ready for this week's adaptation?

Most bird
bodies don't tell much about the bird's life until you look carefully
at the wings, tail, and legs. For this week’s question think carefully
about what is inside the eagle as well as what we see on the outside.

Challenge
Question #15:“In what ways is the eagle's body built for survival?”

1. Address
an e-mail message to: jn-challenge-eagle@learner.org
2. In the Subject Line of your message write: Challenge Question #13 (or
#14, or #15).
3. In the body of EACH message, answer ONE of the questions above.

The Next Bald Eagle Migration Update Will Be Posted on March 24, 2004.